I have seen an idol re-energized. Yagnas were conducted with kalashas filled with water placed next to the fire. The idol was then bathed in the energized water. Are procedures like this mentioned in Agama shastras?

In the Yantras they definitely loose Prana after some years (20 years etc depending on the materials the Yantra is made of ).. not sure about temple idols though..
– RickrossFeb 28 '18 at 16:20

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Yes they perform the ceremony like kumbhabhishekam every twelve years however its not loosing prana but important ritual
– Rakesh JoshiFeb 28 '18 at 22:44

Rather than saying idols lose power, the term is 'sannidhyam'. If we don't keep a place clean, God won't like to reside there.. same with our house, or our heart. Due to lack of perfect achara-anushtana inevitably over years, we need to do additional yagnas to re-purify the place.
– ramMar 1 '18 at 0:32